He could "float like a butterfly, sting like a bee." The young
Muhammad Ali dazzled all who saw him perform in the ring, where his
dancer's footwork and lightning-fast combinations enabled him to win
the world heavyweight championship three times. And out of the ring,
his nonstop chatter, his doggerel verse and his insistence that he was
"the greatest" won him worldwide affection.

But the Ali who checked into the Neurological Institute at New York
City's Columbia-Presbyterian Medical Center last week evoked a much
different emotion. For at least two years, journalists and...